I've got a weird issue with a secure site, where some users reporting that their browsers are showing the site's SSL Certificate as being invalid.
The site is running on a dedicated server running Fedora 17 (i.e. no other virtual hosts are running on that particular web server) and the SSL is through GoDaddy.
The only thing that I can possibly think of as being a possible cause is that there are other (non-secure) domain names that point to the same IP Address, though they're being hosted on another machine. In this setup, I have two web servers with non-routable ips behind a router which has the dedicated public ip as its wan address. Depending on the port (80 or 443), the router forwards the requests to the appropriate web server.
The weird thing that's been confounding me is that the errors are only being reported from some people, not everyone, and I haven't been able to reproduce the issue myself. Are there any glaring issues with my setup and/or can someone suggest a way to even troubleshoot this problem?